This is a brand new Dell WN979 battery. The superior South Korean cells inside the battery cartridge provide longer run times between charges as well as a longer service life than cheaper, lower batteries.

This WN979 battery is rated 11.1 volts and 5200 mAh and will normally last 2.5 hours on a full charge. You can get longer battery life by dimming your screen and closing unused programs.

Each battery is individually tested before shipment and backed by 30 day complete satisfaction guarantee and a 2 Year warranty.

You can expect about 2 hours to 2-1/2 hours of run time with this WN979 battery when new, depending on your energy use. If you are looking for even longer battery run times, check out (our Dell-50XT.

This WN979 battery replaces Dell laptops: Latitude D531 D820 D830 D840 and the Precision M65 series laptops.